Constant-temperature liquid supply apparatus

The present invention relates to a constant-temperature liquid supply apparatus for supplying liquid from a liquid supply source to a processing apparatus while adjusting the liquid to a constant temperature.

In general, in a processing apparatus such as a grinding apparatus and a cutting apparatus, the water temperatures of processing water, cooling water for a spindle, and the like are controlled to constant temperatures. By the supply of the processing water and the cooling water at the constant temperatures, worsening of processing accuracy due to thermal expansion or thermal shrinkage of mechanical parts and damaging of the apparatus itself due to mutual contact of parts, such as seizure of the spindle, are prevented.

Hitherto, there has been known a constant-temperature water supply apparatus for maintaining, at a constant temperature, water supplied to a processing apparatus (see, for example, Japanese Patent Laid-open No. 2020-051716).

The constant-temperature water supply apparatus disclosed in Japanese Patent Laid-open No. 2020-051716 is configured such that water supplied from plant equipment or the like is reserved in a tank and the water is supplied to the processing apparatus while being adjusted to the constant temperature by temperature adjusting means disposed in a channel through which the water in the tank is fed to the processing apparatus by a pump. In addition, for appropriately supplying a quantity of water necessary on the processing apparatus side, the channel of the constant-temperature water supply apparatus is piped in such a manner that water can be circulated in the inside thereof, and the water in the circulation piping is adjusted to the constant temperature. Further, the quantity of water necessary on the processing apparatus side is supplied from the circulation piping.

However, in the constant-temperature water supply apparatus disclosed in Japanese Patent Laid-open No. 2020-051716, the water in the circulation piping is circulated while being maintained at the constant temperature such that the water at the constant temperature can be supplied any time, that is, even when the processing apparatus is out of use. Thus, the constant-temperature water supply apparatus disclosed in Japanese Patent Laid-open No. 2020-051716 has such a problem that power consumption of the constant-temperature water supply apparatus is increased due to the operations of the pump and the temperature adjusting means.

Hence, there is such a problem that, in the constant-temperature water supply apparatus for supplying water to a processing apparatus while adjusting the water to a constant temperature, the power consumption of the constant-temperature water supply apparatus should be suppressed when the processing apparatus is not in operation.

Accordingly, it is an object of the present invention to provide a constant-temperature liquid supply apparatus that is able to suppress power consumption.

In accordance with an aspect of the present invention, there is provided a constant-temperature liquid supply apparatus for supplying liquid from a liquid supply source to a processing apparatus while adjusting the liquid to a constant temperature, the constant-temperature liquid supply apparatus including a housing, an inlet disposed in the housing such that the liquid is allowed to flow from the liquid supply source into the housing, an outlet disposed in the housing such that the liquid is allowed flow out of the housing to the processing machine, a circulation route for circulating the liquid between the inlet and the outlet, a tank that is disposed in the circulation route and accommodates the liquid flowing in through the inlet, a pump that is disposed adjacent to the tank in the circulation route and discharges the liquid accommodated in the tank, a temperature adjusting unit that is disposed in the circulation route and adjusts the temperature of the liquid, an outflow quantity measuring section that measures the outflow quantity of the liquid flowing out through the outlet, an on-off valve that is disposed in the circulation route and controls whether the liquid should be circulated in the circulation route, and a controller that controls at least the pump and the temperature adjusting unit, in which the controller has a first determination section that determines switching from a normal mode of supplying the liquid to the processing apparatus to a stand-by mode of circulating the liquid in the circulation route by controlling the on-off valve, when it is determined that the outflow quantity of the liquid measured by the outflow quantity measuring section is zero, and, in the stand-by mode, the discharge quantity from the pump is set to be smaller than that in the normal mode to thereby lower the power consumption of the pump.

Preferably, the controller stops the operation of the temperature adjusting unit to thereby lower the power consumption of the temperature adjusting unit, in the stand-by mode.

Preferably, the controller has a timer, and the first determination section measures a length of continuation time for which the outflow quantity of the liquid measured by the outflow quantity measuring section is zero by the timer, and, when the length of continuation time exceeds a predetermined length of time, the first determination section determines that the outflow quantity of the liquid is zero, and the controller switches from the normal mode to the stand-by mode.

Preferably, the constant-temperature liquid supply apparatus further includes a thermometer that is disposed on a downstream side of the temperature adjusting unit and measures the temperature of the liquid, and the controller has a second determination section that determines to switch the discharge quantity from the pump to a discharge quantity in the normal mode and operate the temperature adjusting unit, when the temperature measured by the thermometer exceeds a predetermined temperature during the stand-by mode.

The present invention produces such an effect that the power consumption of the constant-temperature liquid supply apparatus can be suppressed.

The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing a preferred embodiment of the invention.

An embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not to be limited by the contents described in the following embodiment. In addition, the constituent elements described below include those which can easily be conceived of by a person skilled in the art and those which are substantially the same. Further, the configurations described below can be combined with one another as required. Besides, various kinds of omission, replacement, or modification of the configuration can be made within such ranges as not to depart from the gist of the present invention.

1 FIG. 2 FIG. 1 FIG. 3 FIG. 1 FIG. A constant-temperature liquid supply apparatus according to the embodiment of the present invention will be described with reference to the drawings.is a block diagram schematically depicting a configuration example of the constant-temperature liquid supply apparatus according to the embodiment.is a perspective view schematically depicting a configuration example of a processing apparatus for which the constant-temperature liquid supply apparatus depicted inis used.is a block diagram schematically depicting a case where the constant-temperature liquid supply apparatus depicted inis in a stand-by mode.

1 8 100 8 1 8 100 8 8 8 8 1 FIG. 2 FIG. 2 FIG. A constant-temperature liquid supply apparatusdepicted inaccording to the embodiment is an apparatus that supplies liquidat a constant temperature to a processing apparatusdepicted in. Note that the liquidat the constant temperature which the constant-temperature liquid supply apparatussupplies is liquidto be supplied to a workpiece or the like at the time of processing the workpiece by the processing apparatusdepicted in, and, in the embodiment, the liquidis pure water and is not used for cooling a spindle or the like. Note that, in the present invention, the liquidmay be city water. In addition, the liquidat the constant temperature means liquidat a temperature of not lower than a predetermined lower limit temperature but not higher than a predetermined upper limit temperature (a temperature higher than the lower limit temperature).

100 100 2 FIG. 2 FIG. The processing apparatusdepicted inis a grinding apparatus that grinds a workpiece. The workpiece to be processed by the processing apparatusdepicted inis such a wafer as a circular plate-shaped semiconductor wafer or optical device wafer having a substrate formed of silicon, sapphire, gallium, or the like. The workpiece is formed with unillustrated devices in regions partitioned by streets set in a grid pattern on a front surface of the substrate.

The devices are, for example, integrated circuit devices such as integrated circuits (ICs), or large scale integration (LSI) circuits, image sensors such as charge coupled devices (CCDs) or complementary metal oxide semiconductors (CMOSs), micro electro mechanical systems (MEMS), or semiconductor memories (storage devices).

100 In addition, in the embodiment, the workpiece has its back surface on the back side of the front surface ground by the processing apparatusto be thinned to a predetermined finished thickness, and is thereafter divided along the streets into the individual device chips.

2 FIG. 100 101 104 105 104 110 120 130 107 140 150 160 170 As depicted in, the processing apparatusincludes an apparatus base, a turntable, a plurality of (in the embodiment, three) holding tablesdisposed on the turntable, a rough grinding unit, a finish grinding unit, a grinding feeding unit, a cassette, an alignment unitwhich is a support unit, a conveying unit, a cleaning unit, and a control unit.

104 101 104 105 The turntableis a disk-shaped table provided on an upper surface of the apparatus base, is provided to be rotatable in a horizontal plane around an axis parallel to a Z-axis direction, and is driven to rotate at a predetermined timing. Note that the Z-axis direction is a direction parallel to the vertical direction. On the turntable, for example, three holding tablesare disposed at regular intervals of, for example, phase angles of 120 degrees.

2 FIG. 105 106 105 106 106 106 106 As depicted in, these three holding tablesare each formed in the shape of a circular plate, and its upper surface is a holding surfaceconfigured by a porous material such as porous ceramic. The holding tableis a table of a vacuum chuck table structure in which the holding surfaceincludes a vacuum chuck connected with an unillustrated suction source, and, with the front surface side of the workpiece mounted on the holding surfaceand with the holding surfacesucked by the suction source, the workpiece is held under suction on the holding surface.

105 104 105 301 302 303 301 In addition, at the time of grinding, the holding tableis driven to rotate around an axis parallel to the Z-axis direction by an unillustrated rotating mechanism. By rotation of the turntable, the holding tablesare each sequentially moved into a conveying-in/out region, a rough grinding region, a finish grinding region, and the conveying-in/out region.

301 105 105 302 105 110 303 105 120 Note that the conveying-in/out regionis a region where the workpiece is conveyed onto the holding tableor conveyed out of the holding table, the rough grinding regionis a region where the workpiece held by the holding tableis subjected to rough grinding (corresponding to grinding) by the rough grinding unit, and the finish grinding regionis a region where the workpiece held by the holding tableis subjected to finish grinding (corresponding to grinding) by the finish grinding unit.

110 111 105 106 105 302 120 121 105 106 105 303 The rough grinding unitis a processing unit having mounted thereto a grinding wheel(corresponding to a processing tool) for rough grinding in which rough-grinding grindstones for rough grinding of the back surface, exposed to the upper side, of the workpiece held by the holding tableare disposed in an annular pattern, whereby the back surface of the workpiece held by the holding surfaceof the holding tablein the rough grinding regionis subjected to rough grinding. The finish grinding unitis a processing unit having mounted thereto a grinding wheel(corresponding to a processing tool) for finish grinding in which finish-grinding grindstones for finish grinding of the back surface of the workpiece held by the holding tableare disposed in an annular pattern, whereby the back surface of the workpiece held by the holding surfaceof the holding tablein the finish grinding regionis subjected to finish grinding.

110 112 111 121 113 123 111 121 106 105 110 120 111 121 113 123 8 1 105 302 303 111 121 105 130 The grinding unitsandhave grinding wheelsandmounted to lower ends (corresponding to tips) of spindles rotated around axes parallel to the Z-axis direction by motorsand, and have the grindstones of the grinding wheelsanddisposed opposite to the holding surfacesof the holding tables. The grinding unitoris so configured that, while the spindle and the grinding wheelorare rotated around the axes by the motororand while the liquidsupplied from the constant-temperature liquid supply apparatusis supplied to the back surface of the workpieces held by the holding tablein the grinding regionor, the grindstones of the grinding wheelorare brought closer to the holding tableat a predetermined feed rate by the grinding feeding unit, whereby the back surface of the workpiece is subjected to rough grinding or finish grinding.

130 110 120 110 120 105 130 102 101 130 115 125 110 120 The grinding feeding unitmoves the grinding unitorin the Z-axis direction, to thereby move the grinding unitorand the holding tablerelatively toward or away from each other. In the embodiment, the grinding feeding unitis provided on an erected columnerected from one end part in a Y-axis direction parallel to the horizontal direction of the apparatus base. The grinding feeding unitincludes a known ball screw provided to be rotatable around an axis, a known motor for rotating the ball screw around the axis, and known guide rails for supporting a spindle housingorof each grinding unitorin such a manner as to be movable in the Z-axis direction.

110 120 111 121 105 105 Note that, in the embodiment, the rough grinding unitand the finish grinding unitare configured such that the axes as centers of rotation of the grinding wheelsandand the axes as centers of rotation of the holding tablesare disposed in parallel to each other with horizontal intervals therebetween, and that the grindstones pass on the centers of the back surfaces of the workpieces held by the holding tables.

107 107 107 108 140 107 The cassetteis an accommodating container that has a plurality of slots for accommodating a plurality of workpieces. The cassetteaccommodates a plurality of workpieces that have or have not yet been subjected to grinding. A pair of cassettesare provided, and are respectively disposed on cassette mounting stands. The alignment unitis a table on which the workpiece taken out of the cassetteis temporarily placed in order to perform alignment of centers.

150 150 151 152 153 The conveying unitis a unit for conveying the workpiece. The conveying unitincludes a conveying-in unit, a conveying-out unit, and a conveying-in/out unit.

151 101 151 140 105 301 The conveying-in unitis formed in the shape of an arm that has at a tip part thereof a suction pad for holding the workpiece under suction, and that is provided on the apparatus basein such a manner as to be swingable around a base end part thereof. The conveying-in unitholds the workpiece that has been aligned by the alignment unitbut has not yet been subjected to grinding on the suction pad under suction and conveys in the workpiece onto the holding tablelocated in the conveying-in/out region.

152 101 152 105 301 160 The conveying-out unitis formed in the shape of an arm that has at a tip part thereof a suction pad for holding the workpiece under suction, and that is provided on the apparatus basein such a manner as to be swingable around a base end part thereof. The conveying-out unitholds the workpiece that is placed on the holding tablelocated on the conveying-in/out regionand that has been subjected to grinding on the suction pad under suction and conveys out the workpiece to the cleaning unit.

153 107 140 160 107 153 The conveying-in/out unittakes out the workpiece that has not yet been subjected to grinding from the cassetteand conveys the workpiece to the alignment unit, and also takes out the workpiece that has been subjected to grinding from the cleaning unitand conveys the workpiece to the cassette. The conveying-in/out unitis, for example, a robot pick including a U-shaped hand, and holds under suction and conveys the workpiece by a U-shaped hand.

160 The cleaning unitcleans the workpiece that has been subjected to grinding, to remove contaminants such as swarf deposited on the ground back surface of the workpiece.

170 100 170 105 110 120 100 170 The control unitis a unit for controlling the above-mentioned constituent units of the processing apparatus. In other words, the control unitcontrols operations of at least the holding tablesand the grinding unitsandto cause the processing apparatusto perform a processing operation on the workpiece. The control unitis a computer that includes an arithmetic processing device having a microprocessor such as a central processing unit (CPU), a storage device having a memory such as a read only memory (ROM) or a random access memory (RAM), and an input/output interface device.

170 100 100 170 The arithmetic processing device of the control unitperforms arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the processing apparatusto the above-mentioned constituent elements of the processing apparatusthrough the input/output interface device. In addition, the control unitis connected to a display unit configured by a liquid crystal display or the like for displaying the status of the processing operation, images, and the like, to an input unit used when the operator registers information concerning the contents of processing, and to an alarm unit that issues an alarm to the operator.

The input unit is configured by at least one of a touch panel provided in the display unit or a keyboard or the like. The alarm unit issues at least one of a sound, light, or a message on the touch panel to issue an alarm to the operator.

100 103 8 1 100 103 8 1 8 105 302 303 100 103 8 1 In addition, in the embodiment, the processing apparatusincludes an on-off valveprovided at a supply port through which the liquidis supplied from the constant-temperature liquid supply apparatus. At the time of grinding the workpiece, the processing apparatusopens the on-off valve, whereby the liquidis supplied from the constant-temperature liquid supply apparatus, and the thus supplied liquidis supplied to the back surfaces of the workpieces held by the holding tableslocated in the grinding regionsandduring grinding. Besides, when the grinding of the workpiece is stopped, the processing apparatuscloses the on-off valve, whereby the supply of the liquidfrom the constant-temperature liquid supply apparatusis stopped.

100 107 108 101 170 170 100 170 110 120 153 107 140 140 151 106 105 301 In the embodiment, the processing apparatusis operated such that the cassetteaccommodating the workpieces with their back surfaces directed upward is placed on the cassette mounting standof the apparatus baseby an operator, processing conditions are registered in the control unit, and the control unitaccepts a direction to start a processing operation from the operator, whereon the processing operation is started. In the processing operation, the processing apparatusis operated such that the control unitrotates the spindles of the grinding unitsandaround the axes at rotational speeds determined by the processing conditions, causes the conveying-in/out unitto take out one workpiece from one of the cassettes, to convey in the workpiece to the alignment unit, causes the alignment unitto perform alignment of the center of the workpiece, and causes the conveying-in unitto support and convey the workpiece onto the holding surfaceof the holding tablelocated in the conveying-in/out region.

100 170 106 105 301 104 105 301 302 303 8 105 110 120 100 170 104 105 301 152 105 301 160 160 107 153 In the processing operation, the processing apparatusis operated such that the control unitcauses the workpiece to be held under suction on the holding surfaceof the holding tablelocated in the conveying-in/out region, rotates the turntable, causes the holding tableholding the workpiece thereon in the conveying-in/out regionto be sequentially moved to the rough grinding regionand the finish grinding region, supplies the liquidwhile rotating the holding tablearound the axis, and subjects the workpiece to grinding sequentially by the rough grinding unitand the finish grinding unit. In the processing operation, the processing apparatusis operated such that the control unitsubjects the workpiece to finish grinding, thereafter rotates the turntable, to cause the holding tableholding the workpiece that has been subjected to finish grinding to be moved into the conveying-in/out region, causes the conveying-out unitto convey the workpiece having been subjected to finish grinding from the holding tablelocated in the conveying-in/out regionto the cleaning unit, cleans the workpiece by the cleaning unit, and thereafter accommodates the workpiece into the cassetteof the conveying-in/out unit.

100 170 104 105 301 160 105 301 105 302 105 303 100 170 104 105 301 106 105 302 303 100 170 107 In the processing operation, the processing apparatusis operated such that, each time the control unitrotates the turntableby 120 degrees, the workpiece that has been subjected to finish grinding is conveyed from the holding tablelocated in the conveying-in/out regionand holding the workpiece to the cleaning unit, the workpiece that has not yet been subjected to grinding is conveyed onto the holding tablelocated in the conveying-in/out regionand not holding the workpiece having been subjected to finish grinding, the workpiece that is held by the holding tablelocated in the rough grinding regionand that has not yet been ground is subjected to rough grinding, and the workpiece that is held by the holding tablelocated in the finish grinding regionand that has been subjected to rough grinding is subjected to finish grinding. In this way, the processing apparatusis operated such that, each time the control unitrotates the turntableby 120 degrees, the workpiece is conveyed onto or out of the holding tablelocated in the conveying-in/out region, the workpiece held on the holding surfaceof the holding tableis sequentially positioned in the rough grinding regionand the finish grinding region, and the workpiece is sequentially subjected to rough grinding and finish grinding. The processing apparatusends the processing operation when the control unithas subjected all the workpieces in the cassetteto rough grinding and finish grinding.

1 4 FIG. 1 FIG. 5 FIG. 1 FIG. 6 FIG. 1 FIG. Next, the constant-temperature liquid supply apparatuswill be described.is a flow chart of an operation carried out repeatedly in the normal mode by a controller of the constant-temperature liquid supply apparatus depicted in.is a flow chart of an operation carried out repeatedly in the stand-by mode by the controller of the constant-temperature liquid supply apparatus depicted in.is a block diagram schematically depicting the flow of the liquid when the liquid is supplied to a processing apparatus of a modification example by the constant-temperature liquid supply apparatus depicted in.

1 8 2 8 100 1 3 4 3 5 3 10 3 20 3 30 40 1 FIG. 1 FIG. The constant-temperature liquid supply apparatusis an apparatus that adjusts the temperature of the liquidsupplied from a liquid supply sourcedepicted into the above-described constant temperature and supplies the liquidto the processing apparatus. As depicted in, the constant-temperature liquid supply apparatusincludes a casing, an inletprovided in the casing, an outletprovided in the casing, a circulation routeaccommodated in the casing, a discharge routeaccommodated in the casing, an outflow quantity measuring section, and a controller.

4 8 2 5 8 100 5 103 100 6 7 5 7 8 100 8 100 The inletis provided for inflow of the liquidfrom the liquid supply source. The outletis provided for outflow of the liquidto the processing apparatus. The outletis connected to the on-off valveof the processing apparatusthrough piping. In addition, in the embodiment, an outlet solenoid valvewhich is an on-off valve is provided at the outlet. The outlet solenoid valvepermits outflow of the liquidto the processing apparatuswhen opened, and restricts the outflow of the liquidto the processing apparatuswhen closed.

10 8 4 5 10 11 12 13 14 15 16 11 10 8 4 11 4 8 2 4 11 8 2 The circulation routeis provided for circulation of the liquidbetween the inletand the outlet. The circulation routeincludes a tank, a supply channel, a pump, a circulation channel, a temperature adjusting unit, and a thermometer. The tankis disposed in the circulation route, and accommodates the liquidflowing in via the inlet. The tankand the inletare connected with each other, and the liquidis supplied from the liquid supply sourcethrough the inlet. The tanktemporarily reserves the liquidsupplied from the liquid supply source.

12 11 8 11 13 11 10 8 11 12 13 8 12 8 12 The supply channelhas one end thereof connected to the tank, and is supplied with the liquidin the tank. The pumpis disposed adjacent to the tankin the circulation route, and discharges the liquidin the tankinto the supply channel. In the embodiment, the pumpdischarges the liquidat a first flow rate (in the embodiment, 25 L/min) into the supply channelwhen driven at 60 Hz, and discharges the liquidat a second flow rate (lower than the first flow rate; in the embodiment, 12.5 L/min) into the supply channelwhen driven at 30 Hz.

14 12 141 142 11 8 12 11 The circulation channelhas its one end connected to the other end of the supply channel, is branched at its center into two branch channelsand, which are connected to the tank, and returns the liquidin the supply channelto the tank.

10 17 18 19 17 10 8 10 17 141 141 142 8 12 11 141 8 12 11 141 In addition, the circulation routeincludes a solenoid valvewhich is an on-off valve, a relief valve, and a second outflow quantity measuring section. The solenoid valveis disposed in the circulation route, and controls whether the liquidshould be circulated into the circulation route. In the embodiment, the solenoid valveis provided in the branch channelwhich is one of the two branch channelsand, permits the liquidfrom the supply channelto return to the tankthrough the one branch channelwhen opened, and restricts the returning of the liquidfrom the supply channelto the tankthrough the one branch channelwhen closed.

17 8 12 11 141 141 8 11 12 14 10 17 8 12 11 141 141 8 11 12 14 10 17 8 10 141 The solenoid valvereturns the liquidfrom the supply channelto the tankthrough the one branch channelby opening the one branch channel, to thereby circulate the liquidin the tankbetween the supply channeland the circulation channelof the circulation route. The solenoid valverestricts the returning of the liquidfrom the supply channelto the tankthrough the one branch channelby closing the one branch channel, to thereby restrict the circulation of the liquidin the tankbetween the supply channeland the circulation channelof the circulation route. In this way, the solenoid valveperforms control as to whether to circulate the liquidinto the circulation routeby opening and closing the one branch channel.

18 142 141 142 8 12 11 142 142 8 142 18 8 12 11 142 8 142 19 8 142 40 The relief valveis disposed in the branch channelthat is the other one of the two branch channelsand, and permits the liquidfrom the supply channelto return to the tankthrough the other branch channelby opening the other branch channelwhen the liquidin the other branch channelreaches or exceeds a set pressure. The relief valverestricts the returning of the liquidfrom the supply channelto the tankthrough the other branch channelby closing itself when the liquidin the other branch channelis less than the set pressure. The second outflow quantity measuring sectionmeasures the flow rate of the liquidflowing in the other branch channel, and outputs the measurement result to the controller.

15 10 8 15 12 10 8 12 15 154 155 154 8 12 8 12 154 155 8 12 8 12 155 15 8 12 154 8 12 155 8 12 The temperature adjusting unitis disposed in the circulation route, and adjusts the temperature of the liquid. In the embodiment, the temperature adjusting unitis disposed in the supply channelof the circulation route, and adjusts the temperature of the liquidflowing in the supply channel. The temperature adjusting unitincludes cooling meansand heating means. The cooling meanscools the liquidflowing in the supply channelwhen driven, but does not cool the liquidflowing in the supply channelwhen stopped. In the embodiment, the cooling meansis a freezer, and its maximum capability is 6.2 kW. The heating meansheats the liquidflowing in the supply channelwhen driven, but does not heat the liquidflowing in the supply channelwhen stopped. In the embodiment, the heating meansis a heater, and its maximum capability is 12 kW. The temperature adjusting unitcools the liquidflowing in the supply channelby the cooling means, and heats the liquidflowing in the supply channelby the heating means, to thereby adjust the temperature of the liquidflowing in the supply channelto the above-mentioned constant temperature.

16 10 8 40 16 8 12 15 12 10 8 12 40 The thermometeris disposed in the circulation route, and measures the temperature of the liquidand outputs the measurement result to the controller. In the embodiment, the thermometeris disposed on the downstream side in the direction of flow of the liquidin the supply channelwith respect to the temperature adjusting unitin the supply channelof the circulation route, and measures the temperature of the liquidflowing in the supply channeland outputs the measurement result to the controller.

20 12 10 5 8 100 5 30 8 5 30 20 8 20 8 5 100 40 The discharge routehas its one end connected to the other end of the supply channelof the circulation route, has its other end connected to the outlet, and discharges the liquidto the processing apparatusvia the outlet. The outflow quantity measuring sectionmeasures the flow rate which is the outflow quantity of the liquidthrough the outlet. In the embodiment, the outflow quantity measuring sectionis disposed in the discharge route, and, by measuring the flow rate of the liquidflowing in the discharge route, measures the flow rate of the liquidflowing out via the outletto the processing apparatus, and outputs the measurement result to the controller.

40 1 40 13 15 17 1 8 100 The controllercontrols each of the constituent units of the constant-temperature liquid supply apparatus. Specifically, the controllercontrols the operations of at least the pump, the temperature adjusting unit, and the solenoid valve, to cause the constant-temperature liquid supply apparatusto perform the operation of supplying the liquidto the processing apparatus.

40 40 1 1 The controlleris a computer that includes an arithmetic processing device having a microprocessor such as a CPU, a storage device having a memory such as a ROM or a RAM, and an input/output interface device. The arithmetic processing device of the controllercarries out arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the constant-temperature liquid supply apparatusto the above-mentioned constituent elements of the constant-temperature liquid supply apparatusthrough the input/output interface device.

1 FIG. 40 41 42 43 41 42 8 100 8 10 17 30 In addition, as depicted in, the controllerincludes a timer, a first determination section, and a second determination section. The timermeasures time. The first determination sectiondetermines switching from a normal mode of supplying the liquidto the processing apparatusto a stand-by mode of circulating the liquidin the circulation routeby controlling the solenoid valvewhen it is determined that the flow rate measured by the outflow quantity measuring sectionis zero.

1 40 5 7 13 8 11 12 15 16 8 12 141 17 8 12 100 20 5 Note that the normal mode is an operation mode of the constant-temperature liquid supply apparatusin which the controlleropens the outletby the outlet solenoid valve, drives the pumpto discharge the liquidat a first flow rate from the tankinto the supply channel, drives the temperature adjusting unitaccording to the result of measurement by the thermometerto thereby adjust the temperature of the liquidflowing in the supply channelto the above-mentioned constant temperature, and closes the one branch channelby the solenoid valveto thereby supply the liquidfrom the supply channelto the processing apparatusvia the discharge routeand the outlet.

100 103 1 13 8 12 100 8 8 2 11 12 100 1 FIG. Note that, in this instance, the processing apparatushas the above-mentioned on-off valvebeing open. Note that, in the normal mode of the embodiment, the constant-temperature liquid supply apparatusis operated such that the pumpdischarges the liquidinto the supply channelat the first flow rate of 25 L/min, and, for permitting the processing apparatusto use the liquidat 25 L/min, the liquidis supplied in the order of the liquid supply source, the tank, the supply channel, and the processing apparatus, as indicated by bold-line arrows in.

1 17 13 8 13 15 13 15 8 12 11 141 14 The stand-by mode is an operation mode of the constant-temperature liquid supply apparatusin which the solenoid valveis opened, the pumpis controlled to set the discharge quantity of the liquidfrom the pumpat the second flow rate lower than the first flow rate in the normal mode, the operation of the temperature adjusting unitis stopped to thereby lower the power consumption of the pumpand the temperature adjusting unitthan that in the normal mode, and the liquidis returned from the supply channelto the tankthrough the first branch channelof the circulation channel.

100 103 1 8 11 12 141 14 8 10 3 FIG. Note that, in this instance, the processing apparatushas the above-mentioned on-off valvebeing closed. Note that, in the stand-by mode of the embodiment, the constant-temperature liquid supply apparatuscirculates the liquidin the order of the tank, the supply channel, and the one branch channelof the circulation channel, to thereby circulate the liquidin the circulation route, as indicated by bold-line arrows in.

42 30 In addition, in the embodiment, the first determination sectiondetermines switching from the normal mode to the stand-by mode by determining that the flow rate measured by the outflow quantity measuring sectionis zero when the length of continuation time for which the flow rate is zero is measured by the timer and the thus measured continuation length of time exceeds a predetermined length of time.

43 15 13 8 16 8 8 8 8 8 8 The second determination sectiondetermines to operate the temperature adjusting unitby setting the discharge quantity from the pumpto the discharge quantity in the normal mode when the temperature of the liquidmeasured by the thermometerhas exceeded a predetermined threshold. Note that the predetermined threshold means that the temperature of the liquidis not lower than a predetermined lower limit temperature but is not higher than a predetermined upper limit temperature higher than the lower limit temperature, and the expression that the temperature of the liquidhas exceeded the predetermined threshold means that the temperature of the liquidhas become below the predetermined lower limit temperature or has exceeded the predetermined upper limit temperature. In the embodiment, the constant temperature of the liquidis 25° C., the lower limit temperature of the predetermined threshold is 20° C., and the upper limit temperature of the predetermined threshold is 30° C. Note that the lower limit temperature of the predetermined threshold may be the same as or different from the lower limit temperature of the above-described constant-temperature liquid, and the upper limit temperature of the predetermined threshold may be the same as or different from the upper limit temperature of the above-described constant-temperature liquid.

41 42 43 40 Note that the functions of the timer, the first determination section, and the second determination sectionmay be realized by carrying out the arithmetic processing according to the computer program stored in the storage device by the arithmetic processing device of the controller, or may be realized by a dedicated processing circuit (hardware) such as a single circuit, a composite circuit, a programmed processor, or a parallel programmed processor.

8 1 4 FIG. 1 FIG. 5 FIG. 1 FIG. Next, an operation of supplying the liquidby the constant-temperature liquid supply apparatusaccording to the embodiment will be described.is a flow chart of an operation carried out repeatedly in the normal mode by the controller of the constant-temperature liquid supply apparatus depicted in.is a flow chart of an operation carried out repeatedly in the stand-by mode by the controller of the constant-temperature liquid supply apparatus depicted in.

1 7 17 13 15 8 2 100 40 100 100 103 8 8 20 8 5 100 8 100 1 FIG. 4 FIG. The constant-temperature liquid supply apparatusopens the outlet solenoid valve, closes the solenoid valve, and drives the pumpand the temperature adjusting unitto thereby supply the liquidsupplied from the liquid supply sourceto the processing apparatusduring processing at the first flow rate, that is, in the normal mode, as depicted in. In the normal mode, the controllerrepeatedly carries out the flow chart depicted in. In the normal mode, during processing by the processing apparatus, the processing apparatusopens the on-off valveto use the liquid, and the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is equal to the flow rate of the liquidused by the processing apparatus.

1 42 40 8 20 8 5 100 30 401 1 401 42 40 8 20 8 5 100 401 4 FIG. In the normal mode, the constant-temperature liquid supply apparatusis operated such that the first determination sectionof the controllerdetermines whether or not the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is zero, in reference to the result of measurement by the outflow quantity measuring section, as depicted in(step). In the normal mode, the constant-temperature liquid supply apparatusrepeats stepwhen the first determination sectionof the controllerdetermines that the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatusis not zero (step: No).

100 100 8 103 8 20 8 20 1 42 40 8 20 8 5 100 401 42 40 30 41 42 402 In the normal mode, when the processing apparatusstops its operation such as grinding, the processing apparatusstops using the liquid, and closes the on-off valve. In this case, the liquidstays in the discharge route, and the flow of the liquidin the discharge routeis stopped. Then, the constant-temperature liquid supply apparatusis operated such that the first determination sectionof the controllerdetermines that the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is zero (step: Yes), the first determination sectionof the controllermeasures the length of continuation time for which the flow rate measured by the outflow quantity measuring sectionis zero by the timer, and the first determination sectiondetermines whether or not the length of continuation time has exceeded a predetermined length of time (step S).

1 401 42 40 30 402 1 42 40 30 402 8 13 15 17 403 The constant-temperature liquid supply apparatusreturns to stepwhen the first determination sectionof the controllerdetermines that the length of continuation time for which the flow rate measured by the outflow quantity measuring sectionis zero has not exceeded the predetermined length of time (step: No). The constant-temperature liquid supply apparatustransitions to the stand-by mode when the first determination sectionof the controllerdetermines that the length of continuation time for which the flow rate measured by the outflow quantity measuring sectionis zero has exceeded the predetermined length of time (step: Yes); in this instance, in the embodiment, the discharge quantity of the liquidfrom the pumpis reduced as compared to the first flow rate and set at the second flow rate, the operation of the temperature adjusting unitis stopped, and the solenoid valveis opened (step).

40 1 42 40 8 20 8 5 100 30 501 8 100 20 100 8 42 40 8 20 8 5 100 501 1 40 8 13 15 502 17 401 5 FIG. 5 FIG. In the stand-by mode, the controllerrepetitively carries out the flow chart depicted in. In the stand-by mode, the constant-temperature liquid supply apparatusis operated such that the first determination sectionof the controllerdetermines whether or not the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is zero, in reference to the result of measurement by the outflow quantity measuring section(step), as depicted in. When the liquidis supplied to the processing apparatusthrough the discharge routeas a result of the processing apparatusstarting to use the liquidagain, for example, the first determination sectionof the controllerdetermines that the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is not zero (step: No), and the constant-temperature liquid supply apparatustransitions to the normal mode. In the embodiment, the controllerincreases the discharge quantity of the liquidfrom the pumpas compared to the second flow rate to set the flow rate at the first flow rate, operates the temperature adjusting unit(step), closes the solenoid valveto transition to the normal mode, and returns to step.

1 42 40 8 20 8 5 100 501 43 40 16 503 1 501 43 40 16 503 The constant-temperature liquid supply apparatusis operated such that, when the first determination sectionof the controllerdetermines that the flow rate of the liquidflowing in the discharge route, that is, the flow rate of the liquidsupplied through the outletto the processing apparatus, is zero (step: Yes), the second determination sectionof the controllerdetermines whether or not the temperature measured by the thermometerduring the stand-by mode has exceeded a predetermined threshold (step). The constant-temperature liquid supply apparatusreturns to stepwhen the second determination sectionof the controllerdetermines that the temperature measured by the thermometerduring the stand-by mode has not exceeded the predetermined threshold (step: No).

1 43 40 16 503 17 8 13 15 504 The constant-temperature liquid supply apparatusis operated such that, when the second determination sectionof the controllerdetermines that the temperature measured by the thermometerduring the stand-by mode has exceeded the predetermined threshold (step: Yes), the solenoid valveis left open, the discharge quantity of the liquidfrom the pumpis set to the first flow rate which is the discharge quantity in the normal mode, and the temperature adjusting unitis operated (step).

1 40 42 8 100 17 8 10 13 15 13 15 As has been described above, the constant-temperature liquid supply apparatusaccording to the embodiment is configured such that the controllerhas the first determination sectionwhich determines switching from the normal mode of supplying the liquidto the processing apparatusto the stand-by mode of controlling the solenoid valveand circulating the liquidin the circulation route, and that, in the stand-by mode, the discharge quantity from the pumpis reduced as compared to that in the normal mode and the operation of the temperature adjusting unitis stopped, to thereby lower the power consumption of the pumpand the temperature adjusting unit.

1 13 15 100 1 154 155 13 8 154 155 15 13 8 154 155 15 As a result, the constant-temperature liquid supply apparatusproduces such an effect that power consumption can be suppressed by restraining the operations of the pumpand the temperature adjusting unitwhen it is determined that the operation of the processing apparatusis stopped. In the constant-temperature liquid supply apparatusaccording to the embodiment, it has been clarified that, in the case where the maximum capability of the cooling meansis 6.2 kW and the maximum capability of the heating meansis 12 kW, when the pumpdischarges the liquidat the second flow rate and operations of both the cooling meansand the heating meansof the temperature adjusting unitare stopped, the power consumption can be suppressed by approximately 37% (a reduction from 5,475 Wh to 2,073 Wh) as compared to the case where the pumpdischarges the liquidat the first flow rate and both the cooling meansand the heating meansof the temperature adjusting unitare operated.

1 42 30 In addition, the constant-temperature liquid supply apparatusaccording to the embodiment is able to restrain erroneous switching from the normal mode to the stand-by mode, since the first determination sectiondetermines the switching from the normal mode to the stand-by mode by determining that the flow rate measured by the outflow quantity measuring sectionis zero when the length of continuation time for which the flow rate is zero has exceeded a predetermined length of time.

1 43 15 13 16 40 1 8 2 8 100 Besides, the constant-temperature liquid supply apparatusaccording to the embodiment has the second determination sectionthat determines to operate the temperature adjusting unitby setting the discharge quantity from the pumpto the first flow rate which is the discharge quantity in the normal mode when the temperature measured by the thermometerduring the stand-by mode of the controllerhas exceeded the predetermined threshold. Hence, the constant-temperature liquid supply apparatusaccording to the embodiment is able to maintain the temperature of the liquidsupplied from the liquid supply sourceat the predetermined threshold even in the stand-by mode, and is able to promptly supply the constant-temperature liquidto the processing apparatusupon transition to the normal mode.

1 8 100 8 100 8 100 8 1 6 FIG. 6 FIG. 1 FIG. 6 FIG. 1 FIG. In addition, the constant-temperature liquid supply apparatusaccording to the embodiment is configured such that, in the normal mode, the flow rate of the liquiddischarged to the processing apparatusmay be greater than the amount of the liquidused by the processing apparatus, as depicted in. Note thatis a diagram schematically depicting a case where the amount of the liquidused by the processing apparatusis smaller than the discharge quantity of the liquidfrom the constant-temperature liquid supply apparatusdepicted in. Note that, in, the same parts as those inabove are denoted by the same reference characters as used above, and descriptions thereof are omitted.

6 FIG. 6 FIG. 100 8 103 1 13 8 12 17 1 8 12 20 100 18 142 10 8 12 8 11 14 142 Note that, in the case depicted in, the processing apparatususes the liquidat a flow rate of 15 L/min, by opening the above-mentioned on-off valve. In this case, the constant-temperature liquid supply apparatusis operated such that the pumpdischarges the liquidinto the supply channelat the first flow rate of 25 L/min, and the solenoid valveis set closed. Hence, the constant-temperature liquid supply apparatusis operated such that, as indicated by bold-line arrows in, part of the liquidfrom the supply channelis discharged through the discharge routeto the processing apparatus, while the relief valvedisposed in the other branch channelof the circulation routeis opened by the pressure of the remaining part of the liquidfrom the supply channel, and the remaining part of the liquidis returned to the tankvia the circulation channeland the other branch channel.

42 30 13 15 Note that the present invention is not to be limited to the above-described embodiment. In other words, various modifications can be made in carrying out the present invention within such ranges as not to depart from the gist of the invention. For example, in the present invention, transition to the stand-by mode may be made immediately upon determination by the first determination sectionthat the flow rate measured by the outflow quantity measuring sectionis zero. In addition, in the present invention, in the stand-by mode, only a reduction of the discharge quantity from the pumpto the second flow rate lower than the first flow rate in the normal mode may be made, without stopping the operation of the temperature adjusting unit.

100 8 1 8 1 In addition, in the present invention, the processing apparatusis not limited to the grinding apparatus that performs grinding while supplying the workpiece with the constant-temperature liquidsupplied from the constant-temperature liquid supply apparatus, and may be a cutting apparatus that performs cutting while supplying the workpiece with the constant-temperature liquidsupplied from the constant-temperature liquid supply apparatus.

The present invention is not limited to the details of the above described preferred embodiment. The scope of the invention is defined by the appended claims and all changes and modifications as fall within the equivalence of the scope of the claims are therefore to be embraced by the invention.